1. Field
The present disclosure relates to a vehicle control system, a motor drive controller, and a management controller.
2. Description of the Related Art
Hitherto, as a vehicle control system in a hybrid vehicle including an internal combustion engine and a motor (referred to below as “drive motor”) to drive the wheels, a vehicle control system is known that includes plural Electronic Control Units (ECUs), including a motor control ECU that controls the drive motor and a management ECU that controls devices other than the drive motor, and two mutually independent communications networks of a first communications network and a second communications network, respectively configured by two independent Controller Area Network (CAN) buses. Accordingly, even if one communications network becomes faulty, necessary communication can be sustained, and drive of the wheels by the drive motor can be continued, using a simple configuration and simple processing (Japanese Unexamined Patent Application Publication No. 2014-118272).
In this vehicle control system, a transmission speed of the second communications network is slower than a transmission speed of the first communications network, and each ECU exchanges travel data necessary for travel control and data for improving travel comfort (referred to below as “comfort improvement data”) over the first communications network, and exchanges the travel data over the second communications network. When the first communications network and the second communications network are both operating normally, the motor control ECU receives the travel data and the comfort improvement data, and performs travel control with an emphasis on comfort. When the first communications network becomes faulty, only the travel data is received through the second communications network. Travel comfort is sacrificed, and only functions essential for travel are executed.
Accordingly, in this vehicle control system, when the first communications network becomes faulty, the transmission processing of each ECU does not change, and only reception processing is changed (namely, changed such that only travel data received over the second communications network is received and employed), thereby enabling faults in the communications network to be handled in a simple fashion.
However, in the related vehicle control system described above, the same data is transmitted redundantly over the two communications networks, since it is necessary to transmit real-time information necessary for vehicle travel control (namely, drive motor control) over both the first communications network and the second communications network at all times. As a result, the utilization rate (the ratio of actually transmitted information (excluding redundant information) against overall communication capacity) of the communication capacity of the first communications network and the second communications network is low, and the amount of electric power used for transmission also increases. Namely, the related vehicle control system described above leaves room for further improvement from the perspectives of effective utilization of communication capacity, as well as energy saving.